Cannot use import statement outside a module when importing this package using Jest

[Robin-Hoodie]

• Follow the recommended steps to configure Jest to run though Typescript
• Create a file where you create a function that uses an imported function from "tiny-secp256k1"
• Create a spec file where you import the function you created above
• Run jest

This results in the following error

({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import { compare } from "uint8array-tools";

SyntaxError: Cannot use import statement outside a module

import { pointMultiply, pointAdd } from "tiny-secp256k1";
^

It seems the compare import from "uint8array-tools" is the culprit here

Downgrading to version 1.1.6 resolves the issue

Happy to create a repro or help out if necessary

[junderw]

This is a jest configuration issue.

Both this package and uint8array-tools are set to use require for node environments and import for browser environments.

Most likely setting your jest environment to node should fix the issue.

[junderw]

Jest ESM support is a separate issue. Right now it's bundling the MJS code as a CJS.

[junderw]

Or maybe it's a babel issue. Assuming you followed that website directions exactly.

[junderw]

I work on a private project that uses ts-jest instead of babel and everything works fine, btw.

[Robin-Hoodie]

I've tried running files through the ts-jest transformer now, with the same result.

Let me see if I can create a repro for this

[Robin-Hoodie]

@junderw Here's a repro https://github.com/Robin-hoodie/tiny-secp256k1-repro

[bufo24]

I am having the same issue

[junderw]

This issue is not with this library. We have used the official NodeJS methods for providing cjs backwards compatibility.

Please follow the issue on the jest repository.

[junderw]

https://github.com/facebook/jest/issues/9771#issuecomment-776681032

Try using a custom resolver.

looks like babel also has the same issue.

[Robin-Hoodie]

Thanks for the input @junderw , I've been able to "resolve" (pun intended) this now

For anyone experiencing the same problem, here's the TLDR:

Jest currently does not support the package.json#exports field (see https://github.com/facebook/jest/issues/9771). Currently Jest plans to add support for it in v28. In case v28 has been released when you're reading this, I'd try just upgrading Jest and see if that resolves the issue.

If v28 has not been released yet or v28 also does not resolve this issue, you can use the suggestion mentioned here I've implemented this as follows:

// jest.config.js
module.exports = {
  resolver: "<rootDir>/jest-resolver.js"
  // any other options go here
}

// ./jest-resolver.js
const enhancedResolve = require("enhanced-resolve");

const resolver = enhancedResolve.create.sync({
  conditionNames: ["require", "node", "default", "import"],
  extensions: [".js", ".json", ".node", ".ts"],
});

module.exports = (request, options) => resolver(options.basedir, request);

@junderw As I understood, adding a package.json#main field would also resolve the issue. Is there a specific reason this has not been added? If you just haven't gotten around to it, let me know and I can create a PR for it.